The 2009–10 Northern Football League season was the 112nd in the history of Northern Football League, a football competition in England.
Division One
Division One featured 19 clubs which competed in the division last season, along with three new clubs, promoted from Division Two: Esh Winning Horden Colliery Welfare Norton & Stockton Ancients
Also, Dunston Federation changed name to Dunston UTS.
League table
Results
Division Two
Division Two featured 16 clubs which competed in the division last season, along with four new clubs: Gillford Park, promoted from the Northern Football Alliance Newton Aycliffe, promoted from the Wearside Football League Northallerton Town, relegated from Division One Seaham Red Star, relegated from Division One
Also, Stokesley Sports Club changed name to Stokesley.